For digital versatile disc (DVD) navigators based on vehicle-mounted terminals, there are two ways to control loading and unloading of discs thereof. The first way is by means of an external microcontroller unit (MCU), but this way requires users to develop on their own processing code for loading or unloading the discs. The second way is by means of a DVD module owned by the vehicle-mounted terminals, where the users can directly invoke interfaces of the DVD navigators. Currently, the function of loading and unloading of discs of the DVD navigators is mainly controlled in the second way because the second way can save the software development cost for the users and release port resources of the MCU. However, one drawback of the second way lies in that: when the DVD module is in a sleep state, the disc cannot be immediately unloaded by pressing a Load/Unload button and can only be unloaded after the DVD module is awakened. The process of awakening the DVD module usually takes a relatively long time of 2-3 seconds, and this is inclined to degrade user experiences.
Accordingly, it is necessary to provide a DVD navigator based on a vehicle-mounted terminal to solve the aforesaid problems.